This dog life jacket is the best investment I have ever made for my organic Poodle. I have size S gekauf and they fit perfectly thanks to the adjustable straps. He is a mänlicher dog and also as everything goes out that nothing strangled or tweaks ;-) It accepts not only the lifejacket but he loved them right the first time to try on. Before he is without this vest approx 2m gone far into the water, has paddled like a madman and now he swims across the pond and all very calm and I do not need more afraid that he goes down to his swimming style :-)